JP2015534013A - Launch control - Google Patents

Abstract

The present invention relates to a launch control unit for selectively involving a revised shift control strategy. The revised shift control strategy is operable to control an automotive automatic transmission and / or internal combustion engine. The launch control unit is configured to receive a brake signal (140) from the foot brake and a torque request (130) from the throttle pedal. In use, the launch control unit is operable to participate in the revised shift control strategy based on receiving a torque request above the upper torque threshold within a predetermined time of receiving a brake signal below the lower brake threshold. . Alternatively, the shift control strategy may be revised when the brake signal (140) is above the brake hold threshold and the torque demand (130) is above the lower torque threshold.

Description

The present invention relates to automobile launch control. In particular, the present invention relates to a launch control unit, a method for controlling the involvement of a revised shift control strategy, a processor and an automobile.

It is known to provide an automobile with a launch control system for starting a vehicle from a stationary position. Launch control systems typically control the upshift speed of the internal combustion engine and transmission, for example, via a dual clutch transmission. The launch control system is activated by pressing the launch control button and selecting the sport operating mode of the vehicle. Thereafter, a foot brake is applied to keep the vehicle stationary and the throttle pedal is depressed. The throttle pedal is typically pushed down to the kick down position to increase engine speed. The launch control system controls the engine speed to, for example, a constant 4000 rpm, but the engine speed may be higher or lower. The driver then suddenly releases the brake pedal, allowing the vehicle to accelerate. The traction control system can then control engine speed to reduce or minimize wheel spin and control transmission upshifts as vehicle speed increases. The clutch pressure can be controlled to allow slips that occur between the friction surfaces to control torque transmission.

The torque demand resulting from pushing the throttle pedal down to the kick down position places a high load on the engine. Subsequent engagement of the transmission at high engine speeds can impose significant mechanical loads, such as causing heating and wear of the transmission clutch. This launch strategy would also not be suitable for vehicles with torque converters that provide fluid couplings for automatic transmissions. For example, unlike a dual clutch transmission, it is not possible to provide a torque converter for controlling torque transmission by changing the clutch pressure.

The present invention is presented in at least certain embodiments to overcome or ameliorate some of the aforementioned shortcomings of prior art launch control units.

Aspects of the invention relate to a launch control unit; a method for controlling the involvement of a revised shift control strategy; a processor; and an automobile as set forth in the appended claims. The launch control unit according to the invention has particular applicability in controlling automatic transmissions and / or internal combustion engines.

Viewed from a further aspect, the present invention relates to a launch control unit or controller for selectively participating in a revised shift control strategy operable to control an automotive automatic transmission and / or internal combustion engine.
The controller or launch control unit is configured to receive a brake signal from the foot brake and a torque request from the throttle pedal,
The controller or launch control unit is operable to participate in the revised shift control strategy based on receipt of a torque request above the upper torque threshold within a predetermined time of receipt of a brake signal below the lower brake threshold.

The standard shift control strategy is implemented for normal driving scenarios, and the launch control unit allows the revised shift control strategy to be selectively involved, for example during vehicle performance tests. To do. In one embodiment, the revised shift control strategy is configured to improve vehicle acceleration. The launch control unit has particular applicability to control an internal combustion engine and / or an automatic transmission during a transmission shift (gear change). The revised shift control strategy may, for example, change the duration of the transmission shift (increase / decrease duration) and / or change the engine power during the transmission shift (the torque transmitted during the transmission shift). Increase / decrease). In at least some embodiments, the revised shift control strategy can reduce vehicle acceleration time. The launch control unit provides an intuitive user interface for engaging a revised shift control strategy. The revised shift control strategy can form part of dynamic launch control.

The launch control unit can be configured to maintain involvement in the revised shift control strategy while the torque demand is above the upper torque threshold. If the torque demand falls below the upper torque threshold, the revised shift control strategy can be uninvolved (disengaged).

The launch control unit can be configured to perform a set-up stage prior to involvement of the revised shift control strategy. The setting phase can include detecting a predetermined brake signal and / or a predetermined torque demand. For example, the setting step may include a brake signal that is greater than or equal to a brake hold threshold at the same time that a torque request greater than or equal to a lower torque threshold is detected. A revised shift control strategy can be prepared once the setup phase is complete.

The launch control unit can be configured to allow the driver to control the engine speed during the set phase to meet a predetermined torque requirement. The launch control unit can optionally output instructions to the driver to set the engine speed to a specific level or range. Alternatively, the launch control unit automatically controls the engine speed, for example to maintain the engine speed within a certain level or operating range during a suitable setting phase to improve vehicle acceleration. Can be configured to. The engine speed can be controlled to avoid or reduce wheel slip while pressure is applied to the brake pedal to keep the vehicle stationary. The launch control unit can also optionally instruct the driver to control the application of pressure to the brake pedal during the setup phase.

The launch control unit may be configured to control the operation of the transmission and / or internal combustion engine during a transmission upshift when a revised shift control strategy is involved. For example, the launch control unit can control the duration of the transmission shift and / or the engine speed during the shift. The launch control unit can increase the time during which the shift takes place and / or reduce or eliminate the decrease in torque during the shift.

The launch controller can be configured to upshift an automatic transmission when a revised shift control strategy is involved. The launch control unit can calculate an optimal time to perform an upshift based on, for example, engine speed and / or available traction. The calculation is based on reaction time to predict peak engine speed (rpm) during transmission upshift and / or time delay from upshift request to ratio start and peak engine speed (rpm). can do.

If a traction event (wheel slip or the like) is detected during vehicle activation, the traction control system can operate to reduce engine torque. The launch control unit can calibrate the timing of the transmission upshift so that it does not coincide with the engine torque reduction by the traction control system. Similarly, the launch control unit can be calibrated so that the timing of the transmission upshift does not coincide with a potential traction event (at least on a dry road surface). The launch control unit can be configured to maintain the involvement of the revised shift control strategy even if a traction event is detected.

Controllers such as paddles and buttons can be provided to allow the driver to manually initiate a transmission shift (either up or down), referred to herein as a “manual shift”. Manual shift can only be performed when the vehicle is in an operating mode that allows manual control, such as drive mode or sport mode. The launch control unit can be configured to allow manual shifts to be performed with a revised shift control strategy involved. For example, the controller can be used by a driver to perform a manual shift. The launch control unit can be configured to allow only part of the shift to be performed manually and the rest of the shift to be automated. For example, the launch control unit allows the driver to perform a manual shift to engage the first gear (for example, if the vehicle is stationary or below a defined speed threshold May be constrained based on vehicle speed to allow engagement of the first gear only at certain times), and subsequent shifts may be configured to allow automatic execution. The launch control unit can be configured to maintain automatic control of the transmission upshift when a revised shift control strategy is involved. For example, if the launch control unit determines that the driver is delaying the upshift unnecessarily, the launch control unit can perform the upshift. Automatic control of transmission upshifts can be suppressed if the revised shift control strategy is disengaged.

The launch control unit is configured to define the upper torque threshold as one of the following: (a) maximum throttle input; (b) a predetermined percentage of maximum throttle input; or (c) throttle kickdown position. can do. The throttle kick down position corresponds to a throttle pedal position for forcing a downshift. A detent or the like can be provided to mark the kick down position. The kickdown position can be detected by a calibratable sensor. A solenoid or actuator may be provided to provide adjustable feedback when the throttle pedal reaches or exceeds the kick down position.

The launch control unit has one or more of the following events: (a) if the torque demand does not exceed the upper torque threshold within a predetermined time; (b) if the torque demand falls below the lower torque threshold; (c) revised shift control. (D) the engine speed exceeds a predetermined engine limit; (e) the steering angle exceeds a pre-defined angle; ) If it is a predefined period since the previous participation in the revised shift control strategy has not expired; (g) if the temperature of the oil is outside the predefined operating range; and (h) If a defined driving mode is not selected, it can be configured to suppress involvement in the revised shift control strategy if is detected. The launch control unit can be configured to suppress the involvement of the revised shift control strategy if other events are detected or predicted.

The launch control unit may have one or more of the following events: (a) when the torque demand is below the upper torque threshold; (b) when the engine speed exceeds a predetermined engine limit; (c) the steering angle is predefined (D) a pre-determined period from when the previous involvement in the revised shift control strategy has not elapsed; (e) a brake signal is received; and (f) measured. If the detected vehicle speed is greater than or equal to the defined maximum vehicle speed, it can be configured not to participate in the revised shift control strategy if detected.

The lower brake threshold may correspond to the vehicle foot brake being partially or fully released.

The lower torque threshold may correspond to an engine speed that is less than or equal to the stall speed of the torque converter for connecting the internal combustion engine to the automatic transmission. Alternatively, the lower torque threshold may correspond to an engine speed that is less than or equal to the stall speed of the torque converter, a state referred to herein as a “partial stall” state. This partial stall condition provides improved starting for the torque converter transmission. In particular, the partial stall condition avoids involvement in the engine protection mode due to operating the engine at a speed that otherwise corresponds to the stall speed of the torque converter for a relatively short time (eg, on the order of seconds). It ’s useful. Setting the lower torque threshold so that the corresponding engine speed is below the stall speed also avoids the need to reduce engine speed to protect the transmission while the vehicle is held stationary be able to. This also means that less engine torque transmission (than that resulting from setting the lower torque threshold at the engine speed corresponding to the stall speed of the torque converter) reduces the brake pressure required to keep the vehicle stationary. It provides improved control for the driver to reduce (which can be exacerbated by the torque multiplying function of the torque converter). The revised shift control strategy may not be involved or suppressed when the torque converter stall protection event is in effect (eg, due to engine torque exceeding the torque converter operating limit). The revised shift control strategy can be disengaged if a torque converter stall occurs within a predetermined time (eg, 5 seconds or more).

The launch control unit described herein can be, for example, a separate control module implemented on a microprocessor. Alternatively, the launch control unit can form part of a vehicle system such as an engine control unit.

In a further aspect, the present invention relates to a motor vehicle comprising the launch control unit described herein.

In another further aspect, the present invention relates to a method for controlling the involvement of a revised shift control strategy for controlling an automatic transmission and / or an internal combustion engine of a vehicle, the method comprising reducing a brake signal below a lower brake threshold. Involved in a revised shift control strategy when a torque demand above the upper torque threshold is detected within a predetermined time period.

The method can include a setting step that includes increasing a brake signal above a brake threshold and simultaneously increasing a torque demand above a lower torque threshold.

The method also maintains involvement in the revised shift control strategy when the torque demand is higher than the upper torque threshold and / or suppresses the revised shift control strategy when the torque demand decreases to a value lower than the upper torque threshold. Or not involved.

The method can include suppressing the involvement of the revised shift control strategy if the torque demand does not exceed the upper torque threshold within a predetermined time or not participating in the revised shift control strategy.

The upper torque threshold may correspond to maximum throttle input or a predetermined percentage of maximum throttle input. The upper torque threshold may correspond to a fully depressed throttle pedal or throttle kick down position.

Detecting a decrease in the brake signal may include determining when the vehicle brake is partially or fully released.

The method may include initiating a cool down period following involvement of a revised shift control strategy. The revised shift control strategy cannot be re-engaged during the cooldown period. The cool-down period can be predefined or calculated based on, for example, measured or modeled temperatures.

A data processor programmed to execute a set of instructions defined to perform the methods described herein.

Within the scope of the present application, the various aspects, embodiments, examples, alternatives, in particular the features described in the above paragraphs and in the claims and / or in the detailed description and the drawings below, It is envisioned that it can be implemented on its own or in any combination thereof. For example, features described in connection with one embodiment are applicable to all embodiments as long as such features do not conflict.

Embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings.

FIG. 1 outlines the procedure for participating in a revised shift control strategy according to the present invention. FIG. 2 outlines the conditions for participation and termination of the revised shift control strategy. FIG. 3 shows a first chart showing the operating parameters of the vehicle at the setting, start-up and acceleration stages of the present invention. FIG. 4 shows a second chart showing the operating parameters in the startup phase. FIG. 5 illustrates a method according to an embodiment of the present invention.

A launch control unit for controlling the operation of an automatic transmission of an automobile according to the present invention will be described. The launch control unit is configured to selectively participate (engage) in a revised shift control strategy to provide dynamic launch control of the vehicle. The revised shift control strategy is configured to provide improved vehicle acceleration from a static or low speed start. The revised shift control strategy allows the driver to complete vehicle performance tests, such as recording vehicle performance times from 0 to 100 km / h (0-62 mph).

The launch control unit in the present embodiment is provided in an automobile having an internal combustion engine connected to an automatic transmission by a torque converter. The torque converter includes a torque converter clutch for locking the torque converter when the input speed and the output speed are close to each other. The transmission is conventional and includes an internal clutch for engaging or disengaging gears during transmission shift (either upshifting or downshifting). The automatic transmission has eight speeds, but the present invention is not limited to this point. In an alternative embodiment, the launch control unit also comprises one or more electrical or mechanical traction machines (such as electric motors or flywheels) and an internal combustion engine for supplying torque to one or more drive wheels, for example. It can be used in a hybrid vehicle.

The launch control unit is in electronic communication with the vehicle system via a communication bus such as a CAN bus, a LIN bus, or a FLEXRAY communication system. In particular, the launch control unit receives a brake signal and an engine torque request. Vehicle braking is controlled by a foot brake that operates a hydraulic brake system, and the brake signal is a measure of hydraulic pressure (bar). Engine torque demand is defined as the maximum engine torque percentage available and is related to throttle pedal position. The throttle pedal has a kick down (KD) detent and forces the transmission downshift by depressing the throttle pedal beyond the detent. A solenoid is provided to allow the position of the kickdown detent to be calibrated for the driver.

To implement transmission shift up / down, the launch control unit is configured to control the operation of the transmission and engine. During upshifts, conventional transmission shift control strategies apply torque reduction to the engine to achieve a smooth or fast gearshift. Although desirable under normal driving conditions, this strategy does not optimize vehicle acceleration. To improve acceleration, a revised transmission shift control strategy can be implemented that reduces / reduces the amount of torque reduction during normal upshifts during transmission upshifts. The revised transmission shift control strategy can optionally be combined with a longer shift time, allowing engine inertia torque to be transmitted to the acceleration boost during upshifts. The revised transmission shift control strategy is suitable for use in, for example, a vehicle shift control strategy to provide improved acceleration during performance testing. A preferred revised transmission shift control strategy has been developed by Germany, Germany, Friedrichshafen, 88038, ZF Friedrichshafen AG. Thus, the launch control unit may optionally be configured to engage the revised transmission shift control strategy only when the torque demand exceeds a predetermined threshold (eg, 90%, 95% or greater or 100%). it can.

The launch control unit provides a human machine interface (HMI) for selectively participating in a vehicle shift control strategy to implement a revised transmission shift control strategy that removes torque during transmission upshifts. The launch control unit operates in three phases: a setup phase, a startup phase and an acceleration phase. The operation of the launch control unit at each stage will be described with reference to the accompanying drawings.

As shown in FIGS. 1 and 2, the setting stage includes a driver operation unit, an output display unit, and a suppression / end unit. The driver action allows the driver to prepare for the launch control unit by selecting drive (D) or sport (S). The driver then selects a vehicle operating mode, for example a dynamic mode or a sports mode. Alternatively, the driver can select a manual shift mode that allows manual up / downshifts. In this embodiment, automatic upshifting is enabled regardless of the operation mode selected by the driver. To prepare the launch control unit, the driver applies mild to moderate pressure (with the left foot) to the foot brake and at the same time, light pressure against the throttle pedal (with the right foot) to generate a torque demand. Apply. Activation is determined when the brake signal is above the brake threshold (at least 2 bar and optionally at least 5 bar) and the torque demand is above the lower torque demand threshold (typically greater than 5% or 10%). The The generated torque demand increases engine speed (typically above 1000 rpm) and the torque converter operates in a partial or complete stall phase when the vehicle is prevented from moving by the brake system To do. The lower torque threshold can be calibrated to set the engine speed to increase or maximize the torque multiplication provided by the torque converter when the vehicle begins to move. The setup phase needs to be completed when the vehicle is stationary or below a minimum vehicle speed threshold. The response of the torque converter may vary based on the speed of the engine response in response to vehicle brake release.

If the launch control unit determines that each of these steps has been completed successfully, a revised shift control strategy will be involved, notifying the driver, eg “ready for dynamic activation”, on the instrument cluster or in the message center. Output to be displayed. During the setup phase, the launch control unit can suppress the involvement of the revised shift control strategy or terminate the revised shift control strategy if one or more of the following events are detected:
(I) if the torque demand is below a cut-off torque threshold (eg 5%);
(Ii) if the brake signal falls below a brake threshold (eg 2 bar);
(Iii) When the rudder angle exceeds a steering threshold (for example, greater than 45 °);
(Iv) When the temperature of oil in the transmission is higher or lower than a predetermined operating temperature range (for example, 30 ° C. to 100 ° C.);
(V) the revised shift control strategy counter indicates that the number of events in the shift control strategy exceeds a predetermined limit (eg, 65535 events or more);
(Vi) if the detected vehicle speed or propeller shaft speed exceeds a predetermined limit (eg, the vehicle speed exceeds 20 mph (32 kph) or the propeller shaft speed exceeds 850 rpm);
(Vii) When the power transmission system protection mode determines that the high throttle pedal exceeds a predetermined time limit when the vehicle is stationary or falls below a vehicle speed limit (for example, 5 seconds or more).
The launch control unit will either disengage or suppress the revised shift control strategy if any of these events are detected, and the driver will have to repeat the setup phase. If the launch control unit does not detect any of these events, the revised shift control strategy remains active and the transmission shift control strategy is in effect. A manual shift mode can be selected during the setup phase so that the user can perform a manual shift using a manual gear selector (e.g., paddle).

After completion of the setup phase, the activation phase is activated when the launch control unit detects: (i) if the brake signal decrease is below the minimum brake threshold; (in combination with) (ii) brake signal Is lower than the minimum brake threshold, and the increase in torque demand within a predetermined time is above or above the upper torque threshold. A decrease in brake signal and an increase in torque demand may occur substantially simultaneously or sequentially (eg, a decrease in brake signal where a higher torque demand is higher than the upper torque threshold, but lower than the minimum brake threshold) Can occur before, after or simultaneously). In this embodiment, the launch control unit reduces the brake signal to zero (ie, the foot brake is released) and increases the torque demand to 100% (ie, full throttle) within 1.5 seconds of releasing the foot brake. ) If involved in the startup phase. The kick-down detent on the throttle pedal can accommodate 100% torque demand, thereby providing tactile feedback to the driver. When the launch control unit determines that the launch phase has been completed, the revised shift control strategy is involved along with the revised shift control strategy. A notification to the driver, such as “Enable Dynamic Activation”, is output for display on the instrument cluster or message center.

During the launch phase, the launch control unit can terminate the revised shift control strategy if one or more of the following events are detected:
(I) When the torque demand is below the upper torque threshold (for example, when the driver does not hold the throttle pedal via the kick-down detent);
(Ii) if the detected vehicle speed or propeller shaft speed exceeds a predetermined limit (eg, the vehicle speed exceeds 20 mph (32 kph) or the propeller shaft speed exceeds 850 rpm);
(Iii) When the steering angle exceeds a steering threshold (for example, the steering angle is larger than 30 °, 45 °, 60 °, or 90 °);
(Iv) When a transmission downshift is requested manually; and (v) During a start-up phase, a transmission upshift is requested manually without having a preselected manual shift mode.

During the start-up phase, the launch control unit according to the present embodiment is used when the vehicle is stationary (or lower than the minimum speed threshold) if the manual shift mode is preselected during the setting phase. Allows manual selection of the first gear. If the manual shift mode is not pre-selected, a manual shift request during the startup phase (or during the following acceleration phase) will cause the launch control unit to terminate the revised shift control strategy. Automatic upshifting is enabled regardless of whether the manual shift mode is selected by the driver.

After the start-up phase, the launch control unit enters an acceleration phase in which the vehicle is accelerated from a stationary position. The revised shift control strategy remains involved when the torque demand is higher than the upper torque threshold (100% in this embodiment). Thus, the revised transmission shift control strategy is used when the vehicle accelerates to its maximum speed (this is before the transmission shift reaches its highest gear, for example, the maximum vehicle speed is the seventh gear. It can be applied to each successive gear change (that can be reached) (ie up to the eighth gear). A notification to the driver, for example “Enable Dynamic Activation”, is displayed in the instrument cluster or message center throughout the acceleration phase. During the acceleration phase, upshift warnings such as amber lights on the instrument cluster can be optionally suppressed.

During the acceleration phase, the launch control unit can terminate the revised shift control strategy if one or more of the following events are detected:
(I) For example, if the detected torque demand falls below the upper torque threshold as a result of the driver lifting the throttle pedal;
(Ii) when the driver disables the dynamic vehicle operation mode;
(Iii) When the steering angle exceeds a steering threshold (for example, the steering angle is larger than 30 °, 45 °, 60 °, or 90 °);
(Iv) When the measured vehicle speed is greater than or equal to the calibratable vehicle speed, for example, when the vehicle speed reaches a defined V _MAX or a predetermined percentage thereof.

The revised shift control strategy counter is provided to count the number of shift control strategy events, and the revised shift control strategy when the total number exceeds a predetermined limit (the limit in this embodiment is set as 65535 events). Involvement of is suppressed. Also, the involvement of the revised shift control strategy is suppressed for a period of time, for example 30 seconds, to allow heat dissipation. A notification to the driver can optionally be output to the instrument cluster or message center to notify the driver that the revised shift control strategy cannot be involved.

The revised shift control strategy according to this embodiment uses each transmission upshift (i.e., shifts 1-2, 2-3, 3) to maintain application of vehicle torque during upshifts to increase acceleration. -4, 4-5, 5-6, 6-7 and 7-8) implement the revised shift control strategy. However, this control strategy is only implemented for some of the upshifts, eg 1-2 and 2-3, and the remaining upshifts, eg 3-4, 4-5, 5-6, 6-7 and 7- For 8, a conventional strategy can be adopted. Thus, it will be appreciated that the revised shift control strategy can be calibrated for a particular vehicle.

The operation of the launch control unit according to the present invention will be described with reference to first and second charts A and B shown in FIGS. 3 and 4, respectively. The first and second charts A and B show the operating parameters of the vehicle during the start-up and acceleration phase over time (seconds). The vehicle operating parameters are expressed as follows:
1. A vehicle speed plot 110 represents vehicle speed (n_ab.ltfInput);
2. Acceleration plot 120 represents vehicle acceleration (accel_filt);
3. Torque demand plot 130 represents the torque demand (dki.ltfInput);
4). The brake pressure plot 140 represents the brake signal (FP_BPR);
5. Engine speed plot 150 represents engine speed (MOT_NMO);
6). Engine torque plot 160 represents engine torque (me_red_abs);
7). Gear request plot 170 represents the requested transmission gear (GETR_RGA_DEST);
8). The current gear plot 180 represents the current transmission gear (GETR_RGA_CUR);
9. Revised shift control strategy status plot 190 represents the revised shift control strategy status (FZNAB_StSpActive) indicating when the revised shift control strategy is valid; and The revised shift control strategy state plot 200 represents a revised shift control strategy state (FZNAB_StateStSP) indicating when the revised shift control strategy was involved.

When the setup phase is complete, while the vehicle is stationary (vehicle speed plot 110), the driver applies a slight pressure to the brake pedal and the brake signal is no longer zero (brake pressure plot 140). The driver initially does not apply pressure to the throttle pedal and the torque demand (torque demand plot 130) is zero. Thereafter, the driver applies an appropriate pressure to the throttle pedal, and the torque demand (torque demand plot 130) increases. If the brake signal (brake pressure plot 140) is higher than the lower brake threshold and the torque demand (torque request plot 130) is higher than the lower torque threshold, the setup phase is complete and the revised shift control strategy is enabled ( Shift control strategy status plot 190). During this phase, the application of pressure to the brake pedal and throttle pedal causes the torque converter to slip while the vehicle is stationary. The torque converter clutch is unlocked, and static torque is supplied to the transmission as the engine speed increases. The transmission clutch is locked and static torque is held in the transmission against the braking force applied to the wheels.

The driver then depresses the throttle pedal beyond the kickdown detent and the torque demand increases to 100% (engine torque plot 160). At least substantially simultaneously, the driver releases the brake pedal and the brake signal (brake pressure plot 140) decreases to zero. The launch control unit determines whether the torque demand (engine torque plot 160) has exceeded the upper torque threshold within a predetermined period of 1.5 seconds immediately after the brake signal (brake pressure plot 140) drops to zero bar. As a result, the launch control unit is involved in the vehicle shift control strategy (shift control strategy state plot 200) to implement the revised transmission shift control strategy. Before the brake pedal is released, a slight wheel slip may occur (represented in FIG. 3 by the detected increase in vehicle speed represented by vehicle speed plot 110), which is optionally Note that it is controlled by the traction control system. After the brake pedal is released and the vehicle starts running, the torque converter continues to slip (unlocked) until the input speed and output speed of the torque converter are close and the torque converter clutch is locked. Torque converter slip and torque converter lock occur independently of the transmission shift point.

If the throttle pedal is held beyond the kickdown detent and the torque demand is constant at 100% (engine torque plot 160), the revised shift control strategy is held engaged (shift control strategy state plot 200). The vehicle accelerates (acceleration plot 120) and its speed increases (vehicle speed plot 110). The launch control unit predicts the appropriate time to perform a transmission upshift (gear demand plot 170) and during a transmission upshift when a revised shift control strategy is involved (shift control strategy state plot 200). The engine is controlled to maintain or increase the transmitted torque (engine torque plot 160). If the throttle pedal remains beyond the kickdown detent (ie, 100% throttle demand), the revised shift control strategy is involved through each transmission upshift until the vehicle reaches its maximum speed. It will be appreciated that in FIG. 3 the first two transmission upshifts (1-2 and 2-3) are shown.

The second chart B shown in FIG. 4 shows an enlarged view of the operating parameters during the startup phase. In the second chart B, the release of the brake pedal and the application of pressure to the throttle pedal occur substantially simultaneously. The vehicle accelerates from a stationary position while minimizing wheel spin, resulting in improved acceleration. The torque demand launch control unit is involved in the revised shift control strategy when the throttle pedal is pushed down beyond the kickdown detent (ie, 100% torque demand), and the revised transmission shift control strategy is in each subsequent upshift. It applies to.

The revised transmission shift control strategy can improve vehicle acceleration in performance tests that can reduce the time taken to accelerate from, for example, 0-100 km / h (0-62 mph). In addition, the launch control unit according to the present invention provides an intuitive interface for the driver.

The launch control unit according to the present invention can be modified to output instructions to the driver at each stage of the process. The launch control unit can also provide coaching tips or suggestions to the driver to improve performance. For example, the launch control unit can propose an optimal engine speed to be reached before the footbrake is released.

FIG. 5 represents the steps of a method 200 according to an embodiment of the present invention. The method 200 controls the involvement of a revised shift control strategy for controlling an automatic transmission and / or an internal combustion engine of an automobile (not shown). Thus, the method can be performed by a launch control unit as described above. The method determines, at 202 and 204, whether the brake signal generated by the driver is greater than or equal to the lower brake threshold and whether the accelerator pedal request generated by the driver is greater than or equal to the lower pedal threshold, respectively. Including. If both 202 and 204 are satisfied, the method proceeds along path 206, which is a revised shift strategy as described above, and involves 208.

The involvement of a revised shift strategy is such that the revised shift strategy is used when the vehicle is driven, or the vehicle adopts the revised shift strategy so that it operates using the revised shift strategy when the vehicle is driven. It should be understood that Thus, it should be understood that the involvement of a revised shift strategy does not require the vehicle to be driven, such as when not stationary.

Proceeding along path 206, the method includes a first timing step 210. If the first timing step is satisfied within a predefined time period, for example, 5 seconds, the method determines at 212 that the brake signal has dropped below the lower brake pressure threshold. This step 212 represents that the driver wants to move or accelerate into the vehicle. If a predefined time limit, e.g., 5 seconds has elapsed, the method releases the revised shift strategy and proceeds to 214. If 212 is satisfied, the method proceeds to a second timing step 216. If the second timing step is satisfied within a predefined time, eg, 1.5 seconds, the method determines at 218 that the accelerator pedal request is greater than or equal to the upper pedal threshold. This step 218 represents that the driver wants to quickly accelerate the vehicle using the revised shift strategy. If a predefined time limit, for example 1.5 seconds, has elapsed, the method releases the revised shift strategy and proceeds to 220. If 218 is satisfied, the method proceeds to 222 where the vehicle is activated or accelerated using the revised shift strategy.

From FIG. 5, the revised shift strategy may not be observed until step 222. This is because the revised shift strategy is used to shift gears. Thus, step 222 may be referred to as a revision shift strategy involvement. However, the revised shift strategy may involve the reaching step 210, for example as input to the vehicle control unit.

FIG. 5 does not show all the exit paths for ending the revised shift strategy. These are described above with respect to the launch control unit, and the method may include an exit path for releasing or suppressing the revised shift strategy.

The launch control unit described herein is described as having a fixed brake and a torque threshold. However, the brake threshold (s) and / or the torque threshold (s) may depend on, for example, ambient temperature, available traction, surface conditions (eg, dry, wet or wet) or surface type, Can be changed dynamically. The launch control unit can be configured to automatically detect one or more of these parameters or can be specified by the driver. For example, a driver override may be provided for any such automatic detection to allow the driver to select specific parameters even if the launch control unit identifies different parameters. Is possible. The selected parameters can be displayed on the instrument cluster or message center with any override information. The launch control system may be configured to change the brake threshold (s) and / or the torque threshold (s) based on vehicle parameters such as tire pressure, tire temperature, tread status. Vehicle parameters can be measured or modeled. The launch control system can also be configured to activate a special traction control (DCS) mode tailored to current operating conditions.

Torque demand is described herein as a percentage of the maximum possible torque demand. It will be appreciated that equivalent techniques for selectively involving the revised shift control strategy described herein can be used. For example, a revised shift control strategy can be engaged based on engine speed.

The launch control unit can be configured to provide additional functionality. The launch control unit can automatically enable the stopwatch function to record time, eg, time to accelerate from 0-100 km / h (0-62 mph). When involved, the launch control unit can suppress other vehicle functions, such as opening and closing a convertible roof, for example. Similarly, when the launch control unit is enabled, it is configured to suppress on-board systems such as stop / start functions and / or air conditioning units to reduce parasitic losses and further improve vehicle acceleration. be able to. The launch control unit can be configured for use with an internal combustion engine, for example, in a hybrid vehicle having a mechanical drive system (such as a flywheel) or an electric drive motor. The launch control unit can control the operation of an electric drive motor or mechanical drive system to boost acceleration during part or all of the startup phase. The available boost can be displayed on the instrument cluster, optionally with additional information such as charging time. The boost display can be used to indicate that the launch control system is suppressed, for example, to allow cooling during a start-up event.

The launch control unit described herein can be applied to two-wheel or four-wheel drive vehicles.

The launch control unit according to the invention is described with particular reference to an automatic transmission in combination with a torque converter. The torque converter provides a fluid coupling between the internal combustion engine and the power transmission device. It will be appreciated by those skilled in the art that the launch control unit can be implemented in a vehicle with a (dry) clutch engagement.

Furthermore, the launch control unit can be implemented in a hybrid vehicle combined with an internal combustion engine having either a mechanical drive system (such as a flywheel energy store) or an electric drive motor. For example, the launch control unit may be configured to control the application of torque to the drive wheels by an electric drive motor or mechanical drive system during a transmission upshift relative to the internal combustion engine. The launch control unit can also be used for continuously variable transmissions, for example continuously variable transmission (CVT) or infinitely variable transmission (IVT).

110 ... Vehicle speed plot 120 ... Acceleration plot 130 ... Torque demand plot 140 ... Brake pressure plot 150 ... Engine speed plot 160 ... Engine torque plot 170 ... Gear demand plot 180 ... Gear plot 190 ... Revised shift control strategy status plot 200 ... Revised Shift control strategy state plot

Claims (22)

A launch control unit for selectively participating in a revised shift strategy operable to control an automotive automatic transmission and / or internal combustion engine,
The launch control unit is configured to receive a brake signal from a foot brake and a torque request from a throttle pedal;
The launch control unit is
Receiving a brake signal above the brake hold threshold,
In response to receiving a torque request above the lower torque threshold,
A launch control unit that is operable to participate in the revised shift control strategy. After being involved in the revised shift strategy, the launch control unit
Receiving a brake signal below the lower brake threshold,
In response to receiving a torque request above the upper torque threshold within a predetermined time of receiving a brake signal below the lower brake threshold,
The launch control unit of claim 1 operable to maintain involvement in the revised shift strategy. A launch control unit for selectively participating in a revised shift control strategy operable to control an automotive automatic transmission and / or internal combustion engine,
The launch control unit is configured to receive a brake signal from a foot brake and a torque request from a throttle pedal;
A launch control unit that is operable to participate in the revised shift control strategy based on receipt of a torque request that is greater than or equal to an upper torque threshold within a predetermined time of receipt of a brake signal that is less than or equal to a lower brake threshold. 4. A launch control unit according to claim 2 or 3, wherein the launch control unit is configured to maintain involvement in the revised shift control strategy while the torque demand is greater than or equal to the upper torque threshold. The launch control unit is configured to perform a setting step prior to involvement in the revised shift control strategy, wherein the setting step detects a torque request that is greater than or equal to a lower torque threshold and simultaneously brakes that are greater than or equal to a brake hold threshold. 5. A launch control unit according to claim 3 or claim 4 dependent on claim 3, comprising detecting a signal. 6. The launch control unit is configured to control operation of the transmission and / or the internal combustion engine during an upshift when the revised shift control strategy is involved. The launch control unit described in the section. 7. A launch control unit according to any one of the preceding claims, wherein the launch control unit is configured to upshift an automatic transmission when the revised shift control strategy is involved. The upper torque threshold corresponds to one of the following:
(A) Maximum throttle input;
A launch control unit according to any one of claims 1 to 7, wherein (b) a predetermined percentage of maximum throttle input; or (c) throttle kickdown position. The launch control unit according to any one of claims 1 to 8, wherein the lower brake threshold corresponds to the foot brake of the vehicle being released. The launch of any one of claims 1 to 9, wherein the launch control unit is configured to suppress involvement in the revised shift control strategy when one or more of the following events are detected: control unit:
(A) the torque request is below a lower torque threshold;
(B) If the vehicle speed is above a predetermined speed limit before participating in the revised shift control strategy;
(C) When the engine speed exceeds a predetermined engine limit;
(D) When the rudder angle exceeds a predefined angle;
(E) a predefined period from when the previous involvement in the revised shift control strategy has not expired;
(F) the oil temperature is outside the predefined operating range; and (g) the predefined driving mode is not selected. The launch control unit according to any one of claims 1 to 10, wherein the launch control unit is configured not to participate in the revised shift control strategy when one or more of the following events are detected:
(B) When the engine speed exceeds a predetermined engine limit;
(C) When the rudder angle exceeds a predefined angle;
(D) if it is a predefined period since the previous involvement in the revised shift control strategy has not elapsed;
(E) when a brake signal is received; and (f) when the measured vehicle speed is greater than or equal to the defined maximum vehicle speed. Any one of claims 4-11 dependent on claim 2 or 3, wherein the launch control unit is configured not to participate in the revised shift control strategy if the torque demand falls below the upper torque threshold. The launch control unit described in the section. The launch control unit according to any one of claims 1 to 12, wherein the lower torque threshold corresponds to an engine speed equal to or lower than a stall speed of a torque converter for connecting the internal combustion engine to the automatic transmission. An automobile comprising the launch control unit according to claim 1. A method for controlling the involvement of a revised shift control strategy for controlling an automatic transmission and / or an internal combustion engine of an automobile, said method comprising:
Receiving a brake signal above the brake hold threshold,
Engaging in the revised shift control strategy in response to receiving a torque request above a lower torque threshold. After involvement in the revised shift strategy,
Receiving a brake signal below the lower brake threshold,
In response to receiving a torque request above the upper torque threshold within a predetermined time of receiving a brake signal below the lower brake threshold,
The method of claim 15, comprising maintaining involvement in the revision shift strategy. A method for controlling the involvement of a revised shift control strategy for controlling an automatic transmission and / or an internal combustion engine of a motor vehicle, wherein a torque demand above an upper torque threshold is a predetermined time for a decrease in brake signal below the lower brake threshold. Involved in the revised shift control strategy if detected within. 18. The method of claim 17, wherein the method includes a setting step that includes increasing the brake signal above a brake threshold and simultaneously increasing the torque demand above a lower torque threshold. The method maintains involvement in the revised shift control strategy when the torque demand is higher than the upper torque threshold, and / or when the torque demand decreases to a value lower than the upper torque threshold. 19. A method according to claim 16 or 17 or 18 comprising not inhibiting or engaging in the revised shift control strategy. A data processor programmed to execute a defined set of instructions for performing the method of any one of claims 15-19. A launch control unit substantially as herein described with reference to the accompanying drawings. A method for controlling the involvement of a revised shift control strategy substantially as herein described with reference to the accompanying drawings.

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